The present invention pertains to an arrangement of a conveying track for containers that are conveyed on the conveying track, are to be filled with articles or bulk material in a filling station via a filling hopper and are located in the filling position, and especially to the part of an automatic commissioning transfer station that feeds the shipping containers to the filling station, positions same under the filling or transfer hopper for the duration of the transfer of the articles or product and subsequently removes them from the filling station.
According to the state of the art, the containers are moved by means of a continuously running conveyor belt in the area of the automatic commissioning transfer unit. The separation of the arriving containers is brought about by a clamping device, which is arranged in front of the transfer station, grasps the respective frontmost container and allows it to move forward only shortly before the filling station becomes free. A second clamping device, which grasps the arriving container and holds same in the correct position until the conclusion of the filling, is located on both sides of the conveyor belt directly below the filling or transfer hopper arranged downstream of the first clamping device. The filled container is subsequently released, carried by the continuously driven conveyor belt in a frictionally engaged manner and is removed from the transfer area. The container change time and thus in many cases the throughput capacity of the entire commissioning unit thus depend on the velocity at which the containers are moved forward cyclically on the conveyor belt in a frictionally engaged manner. It is thus also ensured that containers located in the filling position, especially containers of different heights, are also filled satisfactorily with articles or bulk material, without articles dropping by the side in some cases. Articles falling by the side, which are sometimes expensive, usually break. As a rule, at least the operation of the filling station must be interrupted and the disturbance must be eliminated.
The object of the present invention is to create an arrangement of the above-mentioned type, which makes possible the satisfactory and effective filling of an exactly positioned container located in the filling position with simple means and optionally also permits a more rapid cyclic forward movement of the containers in the area of the filling station.
According to the invention, an arrangement is provided of a conveying track for containers. The containers are being conveyed on the conveying track, are to be filled with articles or with bulk material in a filling station via a filling hopper and are in the filling position. The essence of the present invention is that in the immediate area in front of, in and/or after the filling station, the conveying track has, on at least one side, a circulating toothed belt or chain drive with its own intermittent adjusting drive and container carrier plates located at spaced locations from one another. The toothed belt or chain drive can be brought into a positive-locking engagement with containers which are open at the top and arrive on the conveying track, and by which carrier plates the containers can be brought, in a separated manner, both into the filling position and removed from the filling position after filling in a cyclic and preferably accelerated manner. The containers may optionally be fed again into the conveying track on the output side, wherein adjacent carrier plates which are located in the filling position and extend at right angles to the direction of conveying form a filling shaft wall between the filling hopper and a container to be filled.
In an advantageous embodiment variant, six carrier plates are preferably provided, which are fastened, especially suspended in the circulating toothed belt or chain drive at equally spaced locations, wherein the distance corresponds to the width of the container in the direction of conveying.
The carrier plates are especially thin-walled spring steel plates which are stable in themselves, preferably with a thickness of approx. 0.7 mm.
The carrier plates have slots, especially on the top side, preferably in the vertical direction, which increase the elasticity and generate a spring effect when an obstacle is indeed located in the path of movement and is then overcome.
It is especially advantageous for two identical toothed belt or chain drives with vertical axes as well as with upper strand and lower strand to be provided on both sides of the conveying track, where the said toothed belt or chain drives are of a mirror symmetrical design, wherein the carrier plates are about half as wide as the width of the container at right angles to the direction of conveying and both drives are driven, especially in a cyclic manner, by a common drive motor.
In an especially advantageous variant of the present invention, the toothed belt or chain drive is provided with a stationary vertical container guide wall in the direction of conveying, which is arranged especially between the upper and lower strands of the toothed belt or chain drive, wherein the container guide wall forms, optionally together with the upper strand, a filling shaft wall in the direction of conveying in the area of the filling opening.
The filling hopper itself may be designed as a buffer hopper or be provided with a separate buffer hopper, which contains a horizontal slide, which closes the filling opening and can be opened, wherein the horizontal slide, which preferably has a two-part design, opens only when a container is positioned in the filling position and is otherwise closed.
In particular, an emergency means is provided for introducing and removing the containers to be filled in a cyclic manner especially in case of failure of the operation of the toothed belt or chain drive.
The emergency means comprises on each side two lateral stoppers, by which containers running through the filling station on a continuously driven conveyor belt can be positioned in the filling position as well as in the waiting position located in front of the filling position by lateral friction engagement and released.
The sensor mechanism of the adjusting drive of the toothed belt or chain drive or toothed belt or chain drives as well as of the emergency means that is optionally present comprises especially five photoelectric cells, an inductive transducer and a scanner, wherein an additional stopper for separating the containers, which can be put into the path of movement of the containers being delivered or can release the path of movement of the containers being delivered, is provided in the conveying track on the input side of the filling station.
The entire unit may be arranged such that a single continuous conveying track is provided in front of, in and after the filling station, preferably as a belt conveyor or belt drive.
The conveying track may be interrupted in the area of the circulating toothed belt or chain drive and have a separate belt conveyor or belt drive with a separate drive.
The input-side conveying track located in front of the toothed belt or chain drive may be a conveyor belt, an accumulating roller conveyor without impact pressure or a driving roller conveyor with impact pressure.
The belt conveyor or belt drive may also have a stationary upper sliding surface in the area of the filling position, and the belt conveyor or belt drive may be offset downward in parallel via deflecting rollers in the area of the sliding surface.
The change of containers can be carried out by the present invention at a filling station preferably in an accelerated manner and especially accurately. The container to be filled is positioned exactly in the filling position and is filled without problems. The containers (cardboard boxes or the like) are moved forward in a cyclic manner very rapidly by a flat carrier under a transfer hopper (buffer hopper) in a positive-locking manner. The essence of the present invention is especially that when the products fall off from the transfer hopper into the container located underneath, which may additionally have varying heights (h or hxe2x80x2), no products can fall by the side. This is achieved according to the present invention by the shaft-like design of the opening of the transfer hopper up to the opening of the container, regardless of the height of a container. The opening is formed at right angles to the direction of conveying by the carrier plates or carrier aprons themselves, which determine the overall opening together with lateral baffle plates.
To prevent any products from falling by the side, the loading gauge of the so-called indexer is adjusted to the containers or cardboard boxes such that when viewing, e.g., in the front and behind in the direction of conveying, there is only an overall clearance of about 6 mm. The container or cardboard box consequently has only an overall clearance of about 6 mm in the direction of conveying. Due to the fact that the other products have a minimum size of about 12 mm to 15 mm, no product can fall by the side during filling.
In particular, the indexer has a toothed belt or chain drive on the left and right on the side of the container with vertical axes. This drive is driven by a single motor operator or adjusting drive by means of a common chain or a common double-toothed belt. In particular, six carrier plates, made preferably of spring steel, which represent approximately half the width of the container, are mounted at each toothed belt or chain drive. Due to the fact that the left-hand and right-hand toothed belt or chain drives are synchronized by means of a drive, it is possible for the carrier plates to move toward the container under the transfer site in a cyclic manner. In combination with the transfer site and the container, the carrier plates or aprons form at this moment a shaft, which is so narrow that even the smallest products are unable to fall by the side.
Furthermore, an emergency property is also provided. Should the lateral drive or the carrier plates no longer be able to function, it is possible to continue the movement at least in an emergency operation by removing the carrier plates located in the passage (preferably a total of four here-in case of six carrier plates arranged at equally spaced locations on each side) and by the sensor actuation of two stoppers, which fix the container in the transfer position or in the waiting position.
The sensor mechanism comprises five photoelectric cells, an inductive transducer and a scanner. Furthermore, there is a stopper in order to let the containers enter one by one. In addition, there are two more stoppers, which determine the position of the containers in case of a possible emergency operation, in which some of the carrier plates are removed and are no longer functional.
With respect to the state of the art discussed in the introduction, the frictionally engaged carrying of the containers is replaced by the present invention with a positive-locking carrying, namely, by means of the carrier plates provided according to the present invention, which can engage the containers of the conveying track which are to be moved cyclically into the filling station.
On the input side of the filling station, the carrier plates grasp behind the containers and optionally permit a high acceleration of the containers from the standing position, doing so by means of a carrier plate engaging the rear side of the container, which rear side faces away from the direction of conveying. Since the positioning of the containers takes place in a positive locking manner and not by clamping the containers, as according to the state of the art, it is possible to use according to the present invention not only comparatively stable containers, e.g., containers made of plastic, but also containers made of more sensitive material, e.g., pasteboard.